In production of a semiconductor device, a semiconductor chip is adhered and fixed to a substrate or another semiconductor chip in a bonding step. Recently, an adhesive, an adhesive film or the like is likely to be used for bonding a semiconductor chip.
For example, Patent Document 1 discloses an adhesive film for an insulating layer which has a minimum viscosity measured at a heat adhesion temperature by a capillary rheometer method of 100 to 2000 Pa·s in a semiconductor device comprising a semiconductor chip, a flexible wiring substrate, and an insulating layer between them. Patent Document 1 discloses that the adhesive film for an insulating layer disclosed in that document is excellent in film infusion control, heat resistance, and circuit-filling properties.
Meanwhile, semiconductor devices are further reduced in size and further integrated recently, leading to production of, for example, a flip chip having a plurality of protrusions (bumps) as electrodes on the front face and a stacked chip in which a plurality of thinly ground semiconductor chips are stacked. Moreover, production process is further automated for efficient production of such a compact and highly-integrated semiconductor device.
In the recent automated bonding step, a camera recognizes a pattern or position indication on a semiconductor chip to perform alignment of the semiconductor chip. On that occasion, the pattern or position indication is recognized through an adhesive on the semiconductor chip. Therefore, the adhesive used for bonding is required to have a transparency to the extent where the camera can sufficiently recognize the pattern or position indication.
However, a conventional adhesive contains a large amount of fillers for realizing excellent bonding reliability by lowering the linear expansion coefficient of its cured product, causing lowering of the transparency. As a result, recognition of a pattern or position indication with a camera becomes difficult and improvement in productivity of a semiconductor device is problematically disturbed.